Sewing-machine trimmer



(No Model.)

71 'v hzea s e s.-

A. WARREN.

SEWING MAGHINB TRIMMER.

Patented May 22,1883.

To all whom it may concern PATENT O F CE, it

ALONZO WARREN, or; BOSTON, MASSACHUSETTS.

SEWING-MACHINE TRIMMER.

SPECIFICATION formingpart of Letters Patent No. 278,300, dated May 22, 1883,

i Application filed February 9,1883. (No model.)

Be it known that I,ALoNzo WARREN, of

: Boston, in the county of Suffolk and State of and in a line parallel with the stitching.

Massachusetts, haveinven ted certain Improve- .ments in Sewing-Machine Trimmers, of which the following is a specification.

This invention has for its object toprovide 1 an improved attachment for sewing-machines for the purpose of trimming loosely-woven or knit fabrics while the same are being stitched,

My invention' consists in twoco-operating cutting or shearingblades arranged and opf eratin g, as hereinafter described, to alternately clear and enter the throat-plate of the machine,

and to gather a portion of the work and cut it in a substantially.vertical direction, one of said blades moving in such direction that it I constitutes a helper or auxiliary for the feedso ingdcvices of the machine. i

The invention also consists in the form and arrangement of the cutting-edges, whereby thecuttingaction is caused to commence at or jnea-r-the points of the blades and progress gradually to their inner ends, all of which I will now proceed to describe.

Of the accompanying drawings, forming a part of this specificatiomFigure 1 represents 1 I a perspective view of a portion of a sewing- I13P Zand 3 represent elevations of my improved attachment in different positions. Fig. 4 repmachine provided with my improvement. Figs.

resents an enlarged view, showing the cutters in the act of grasping the material.

The same letters of reference indicate the same parts in all thefigures.

In carrying out myinvention I secure to any i a 7 suitable part of the overhanging arm or gooseneck A of a sewing-machine a depending standard, a, to which I pivot, at b,- ablade, c,

having its cutting-edge formed on a re-entrant curve and terminating in a sharp point yadapted to easily penetrate a loose textile fabfric, such as hosiery or-material of liketexture.

The blade 0 is adapted to oscillate on its pivot in. a substantially vertical plane, and is placed a in such relation to the throat-plate or bed of the machine that when pressed downwardly from the position shown in. Fig. 2 its point will penetrate the work on said plate or" bed and enter a slot therein. i i 1 d represents a co-operating blade pivoted at slight re-entrant curve, and is in rubbing con-.

tact with the cutting-edge c. The shank 01 ot the blade 01 is extended upwardly, and is adapted to be operated by a moving part of the machine,.so that when the machine is in operation the blade 4 will be reciprocated vertically. In the present instance the shank d is pressed upwardly a suitable distance by a spring,f, and is arranged so that the oscillatmg lever g, in moving downwardly, will strike and depress said shank. Any other suitable means for reciprocating the blade (1 maybe employed without departing from the spirit of my invention. It will be seen that when the blade d is vertically reciprocated it oscillates the blade 0 on its pivot. When the blade at moves downwardly the point of the blade 0 penetrates the work audits cutting-edge moves crosswise of the cutting-edge of the blade d, so as to out the material interposed. The curvature of said cutting-edges is such that their points meet firstafter thepointof theblade c has penetrated the material, aportion of the material beinglth us'gathered or compressed between the two blades and cut by a gradual upward progressot the cutting action, or, in other words, of the point of contact of the two blades from their outer to their inner ends, the most of the cutting being performed at the upperportious of the cutting-edges, or near the pivot e, that connects the twoblades, so that the material will have less tendency to spring the blades apart than in ordinary shear-blades, in which the cnttingaction commencesnear the pivot and progresses away therefrom. :The blades 0 d are so arranged relatively to the needle that when said blades descend, the blade dwill enter the cut made by the preceding stroke, while the blade 0 will penetrate the material-at a point in advance of the end of said out, the two blades cooperating in severing the'interposed or gathered portion of the material,and thus extending the cut to the point penetrated by the blade 0. Both blades in operation are alternately raised above the throat-plate of the machine, so that the latter is clear and the work can be moved freely thereon, and depressed so asto enter a slot -in said throat-plate, the cutting being performed duringthe downward movement. The

V pivot b of theblade c is so located that when tion opposite to that in which the work is fed,

ments the blades have been so formed and arsaid blade is swung downwardly to penetrate the work it will also move to some extent in the same direction that the work is fed. Although in the machine illustrated in the drawings this movement of the blade 0 occurs after the needle has penetrated the work, and the feed has ceased to operate, said movement in effect helps the feed by preventing anypressure on the work in the opposite direction to that in which the work is moved bythe feed. In all shears heretofore there has been a tendency to crowd the work backward] y orin a directhis tendency increasing as the shears become dull. The work therefore sometimes yields or slips before the shears, and is bunched up or displaced backwardly by the action of the shears, so that when the needle rises the work will creep backwardly over the feed-dog to some extent and partially neutralize the feeding action of the latter. Such -a result cannotbe produced by the operation of my improved blades. It is obvious that the descent of the needle may be differently timed, so that the described movement of the blade 0 will occur wholly orin part before the needle has penetrated the work, and while the latter is being moved by the feed-dog. In such case the blade 0 will act directly to help the feed. The two features above described-viz.,rising and falling movement of the two blades, the progress of the cutting action from the points toward the pivot of the cutting-blades, and the feed-helpingaction of the blade c-distinguish my invention from all cutting attachments heretofore employed having two moving shearblades. Heretofore in such cutting attachranged that the cutting action has progressed outwardly from the pivot to the points of the blades, as in ordinary shears, and in a direction opposite to the direction of the feed. The work therefore has a tendency to spring the blades apart and cause them to cut imperfectly, and the blades in approaching each other have a tendency to press the work backwardl y, this latter tendency being greater when the cutting-edges are (lull. These objections are entirely obviated by my invention.

I do not limit myself to the particular form and arrangement of the blades 0 01 shown and described, as the same may be variously modifled without departing from the spirit of my invention.

I claim-- 1. A trimming attachment for sewing-machines, composed of two co-operating shearblades adapted to rise and fall, so as to alternately clear and enter the throat-plate, and to cut the material during their downward movements, as set forth.-

2. A trimming attachment for sewing-machines, composed of two co-operating shearblades adapted to rise and fall, so as to alternately clear and enter the throat-plate and to cut the material during theirdownward movement, one of said blades having a substantially vertical movement and the other amovement in the direction of the feed, as set forth.

3. A trimming attachment for sewing-machines, composed of a piercing and cutting blade adapted to oscillate in a substantially vertical plane, and a reciprocating blade pivoted to said oscillating blade and imparting motion thereto, said blades being formed at their cutting-edges, substantially as described, to gather and cut a'portion of the material at each downward movement and prevent the work'from pressing baokwardly against the .feed, as set forth.

4. Atrimming attachment for'sewing-machines, composed of a piercing and cutting blade adapted to oscillate in a substantially vertical plane, and a reciprocating blade pivoted to said oscillating blade and imparting motion thereto, said blades being formed and arranged, substantially as described, to gather the material at their points and cut the same by a progress of the cutting action of the blades from the outer to the inner ends thereof, as set forth.

In testimony whereofI have signed my name to this specification, in the presence of two subscribing witnesses, this 7th day of February, 1883.

ALONZO WARREN.

Witnesses:

G. 1*. BROWN, A. L. WHITE. 

